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A paleoparasitological investigation of a vertebrate coprolite from the Huai Hin Lat Formation (Upper Triassic) was carried out. Five morphotypes of potential parasite eggs or sporocysts were identified in the coprolite by microscopic analysis using thin section technique. The rounded or oval shape and thick shell of one of the five morphotypes suggests that it belongs to nematode of the order Ascaridida. Systematic assignment of other morphotypes cannot be done in detail but suggests that the host was parasitized by different species of parasites. This is the first record of parasites in terrestrial vertebrate hosts from the Late Triassic in Asia and it provides new information on parasite-host interactions during the Mesozoic era., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Nonsrirach et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Because parasite data reveal essential information about the behavior and history of their hosts, it is possible to use them as tracers of host evolution. A table built from the analysis of the data contained in the book by Ashford and Crewe "The Parasites of Homo sapiens" allows counting and cross comparing the parasites according to the main descriptors used by the authors: Taxonomic groups, for each group number of parasites species identified in humans; Status, numbers of reported human cases and their dispersion; Geographic distribution, parasite specific richness recorded in biogeographic regions; Habitat, parasite location in or on the human body; Transmission, contamination pathways to man; Hosts, non-human hosts, which have a role in the maintenance of a parasite; Host-specificity status, relative role of man or other hosts in the maintenance of parasite populations. A strong positive correlation is observed between the number of parasites species recorded in humans and the global parasite species richness for each taxonomic group. About 74% of the parasites recorded in humans are rare, sporadic or nowhere common; 10% only are common or abundant worldwide. The Palearctic exhibits the highest parasite species diversity; the Oriental, Nearctic, Neotropical and Aethiopian regions have roughly similar richness values; the Australian Region is the poorest. Earliest domesticated animals, such as dog, cat, cattle or pig, share more parasite species with Humans than tardily domesticated as horse, rabbit or camel. More than one third of our parasites have elected our alimentary canal as a home and about two third are using the digestive tract path for contamination. Time of occupancy of new territories, diversity in feeding habits and commensalism with other animals, widely explain Human particular parasite richness. As suggested by the authors: "There must be few parasitic species which have never had the opportunity to infect a human"., (Copyright © 2022. Published by Elsevier B.V.)

A new rictulariid nematode Pterygodermatites (Mesopectines) valladaresi n. sp., parasite of the house mouse Mus musculus (Rodentia: Muridae) in the Canary Islands (Spain) is described by means of light and scanning electron microscopy. The new species belongs to the subgenus Mesopectines characterized by a more or less dorsal orientation of the buccal capsule, the presence of three oesophageal teeth, the morphology of the oral denticles and the Spirurida type of arrangement of caudal papillae in males. The most discriminant characteristics between the new species and the existing species in the subgenus Mesopectines are (a) the number of cuticular projection pairs (62-64), (b) the size of right and left spicules (respectively, 62-90 µm and 123-139 µm), (c) the number of midventral fans in males (3-4), (d) the number of prevulvar/total cuticular projection pairs (38-42/63-71), (e) the posterior differentiation of combs into spines in relation to the position of the vulva and (f) the anterior position of the vulva in relation to the oesophagus-intestine junction in females. Parasitized hosts and geographical distribution are also useful criteria to distinguish P. (Me.) valladaresi n. sp. from the remaining species of the subgenus. In addition, the cox1 sequence of the new species is provided and compared with available data of related species., (© J. Miquel et al., published by EDP Sciences, 2022.)

Parasite hybrid zones resulting from host secondary contact have never been described in nature although parasite hybridization is well known and secondary contact should affect them similarly to free-living organisms. When host populations are isolated, diverge and recontact, intimate parasites (host specific, direct life cycle) carried during isolation will also meet and so may form parasite hybrid zones. If so, we hypothesize these should be narrower than the host's hybrid zone as shorter parasite generation time allows potentially higher divergence. We investigate multilocus genetics of two parasites across the European house mouse hybrid zone. We find each host taxon harbours its own parasite taxa. These also hybridize: Parasite hybrid zones are significantly narrower than the host's. Here, we show a host hybrid zone is a suture zone for a subset of its parasite community and highlight the potential of such systems as windows on the evolutionary processes of host-parasite interactions and recombinant pathogen emergence., (© 2018 John Wiley & Sons Ltd.)

Understanding why some exotic species become widespread and abundant in their colonised range is a fundamental issue that still needs to be addressed. Among many hypotheses, newly established host populations may benefit from a parasite loss (“enemy release” hypothesis) through impoverishment of their original parasite communities or reduced infection levels. Moreover, the fitness of competing native hosts may be negatively affected by the acquisition of exotic taxa from invaders (“parasite spillover”) and/or by an increased transmission risk of native parasites due to their amplification by invaders (“parasite spillback”). We focused on gastrointestinal helminth communities to determine whether these predictions could explain the ongoing invasion success of the commensal house mouse ( Mus musculus domesticus ) and black rat ( Rattus rattus ), as well as the associated decrease in native Mastomys spp., in Senegal. For both invasive species, our results were consistent with the predictions of the enemy release hypothesis. A decrease in overall gastrointestinal helminth prevalence and infracommunity species richness was observed along the invasion gradients as well as lower specific prevalence/abundance ( Aspiculuris tetraptera in Mus musculus domesticus , Hymenolepis diminuta in Rattus rattus ) on the invasion fronts. Conversely, we did not find strong evidence of GIH spillover or spillback in invasion fronts, where native and invasive rodents co-occurred. Further experimental research is needed to determine whether and how the loss of gastrointestinal helminths and reduced infection levels along invasion routes may result in any advantageous effects on invader fitness and competitive advantage. [ABSTRACT FROM AUTHOR]

We summarize the current knowledge on parasitism-related invasion processes of the globally invasive Rattus lineages, originating from Asia, and how these invasions have impacted the local epidemiology of rodent-borne diseases. Parasites play an important role in the invasion processes and successes of their hosts through multiple biological mechanisms such as 'parasite release,' 'immunocompetence advantage,' 'biotic resistance' and 'novel weapon.' Parasites may also greatly increase the impact of invasions by spillover of parasites and other pathogens, introduced with invasive hosts, into new hosts, potentially leading to novel emerging diseases. Another potential impact is the ability of the invader to amplify local parasites by spillback. In both cases, local fauna and humans may be exposed to new health risks, which may decrease biodiversity and potentially cause increases in human morbidity and mortality. Here we review the current knowledge on these processes and propose some research priorities. [ABSTRACT FROM AUTHOR]

We investigate the determinants of macroparasite species richness of Iberian carnivores. For this, we used the parasitological data collected on 14 species of carnivores over a 10-year period. These previously unpublished data permitted to estimate parasite species richness using estimators of species richness, i.e. Jackknife first order and Chao 2. Most of the parasite species were rare, with low prevalence. Potential determinants were investigated as possible factors explaining the variability of parasites species richness among carnivores host body mass, host geographical range, host longevity and host density. Using independent contrasts, we found positive relationships between residuals of estimates of parasite species richness and residuals in host density, and between residuals of estimates of parasite species richness and residuals in host range. These results are discussed in terms of risk of extinction and invasion abilities related to a possible investment in immune defences correlated with parasite diversity. [ABSTRACT FROM AUTHOR]

Host–parasite interactions are influenced by present and past eco‐evolutionary interactions and the local environment. An ecological community defines the potential host range of each parasite and the potential parasite diversity of each host species. Past and present processes translate potential to realised interaction niches of parasite and host species. Host–parasite interactions are antagonistic, which may slow the saturation of their interaction niches. Intervality, a property of bipartite networks, measures saturation of interaction niches. Intervality of a community increases as the interaction niches of species of one guild (e.g. hosts) become saturated for their interactions with another guild (e.g. parasites). Characteristics driving intervality in host and parasite communities are largely unknown, as well as the effect of environmental change on intervality of these communities. In our study, we assess if the characteristics ‘phylogenetic relatedness' and ‘overlap in ecological interactions' explain intervality of rodent host–helminth parasite communities. In addition, we contrast intervality of these communities from habitats that differ in their history of human‐driven modification. We performed the analyses for the interaction niches of both parasites and hosts, independently. Our results indicated that host and parasite communities were non‐interval or significantly less interval than expected by chance. Phylogenetic relatedness and overlap in ecological interactions did not explain the maximum values of intervality. We speculate that antagonistic coevolution in host–parasite communities may hinder communities to reach saturation, which would explain why it is difficult to find the characteristics that explain intervality of a community. Interestingly, intervality of the interaction niche of parasites (host range) increased with habitat modification (i.e. saturation increased), whereas intervality of the interaction niche of hosts (parasite diversity) decreased as habitat modification increased. These opposite trends suggest that interaction niches of parasites and hosts respond differently to habitat modification. [ABSTRACT FROM AUTHOR]

Describes a new species of an oxyurid nematode from the large intestine of the lacertid lizard Podarcis sicula from Italy. Differences between Spauligodon aloisei and other species of the genus by a combination of morphological and metrical characters; Tail length and location of the excretory pore and vulvar opening.

• Multimammate mice were trapped in Morogoro (Tanzania) and checked for pathogens • Helminths, Bartonella, Anaplasma and Hepatozoon were detected and linked to host factors • Infection probability of Anaplasma and Bartonella was higher in adults than juveniles • Less explorative mice had a higher infection probability with Bartonella • Mice infected with Bartonella are more likely to be co-infected with helminths Advances in experimental and theoretical work increasingly suggest that parasite interactions within a single host can affect the spread and severity of wildlife diseases. Yet empirical data to support predicted co-infection patterns are limited due to the practical challenges of gathering convincing data from animal populations and the stochastic nature of parasite transmission. Here, we investigated co-infection patterns between micro- (bacteria and protozoa) and macroparasites (gastro-intestinal helminths) in natural populations of the multimammate mouse (Mastomys natalensis). Fieldwork was performed in Morogoro (Tanzania), where we trapped 211 M. natalensis and tested their behaviour using a modified open-field arena. All animals were checked for the presence of helminths in their gastro-intestinal tract, three bacteria (Anaplasma, Bartonella, and Borrelia) and two protozoan genera (Babesia and Hepatozoon). Besides the presence of eight different helminth genera (reported earlier), we found that 19% of M. natalensis were positive for Anaplasma, 10% for Bartonella, and 2% for Hepatozoon species. Hierarchical modelling of species communities was used to investigate the effect of the different host-related factors on these parasites' infection probability and community structure. Our results show that the infection probability of Bartonella increased with the host's age, while the infection probability of Anaplasma peaked when individuals reached adulthood. We also observed that less explorative and stress-sensitive individuals had a higher infection probability with Bartonella. Finally, we found limited support for within-host interactions between micro-and macroparasites, as most co-infection patterns could be attributed to host exposure time. [ABSTRACT FROM AUTHOR]